I switch back and forth between a Spector Euro Rebop and one of several different 4-string basses I own.
I have always approached a 5-string bass as an entirely different instrument - not a standard bass with an extra string. So much so that I made a decision when I first got mine
not to play any of my favorite riffs or usual progressions on it. Not that it turned out to be necessary in the end. My fiver feels and sounds different than my usual basses. Enough so that my technique and note choices change completely whenever I play it. And without me forcing myself to do it. Or even think about it really.
Stylistically I play the 5-string differently as well. I tend to veer toward a more chordal and melodic style than the usual rhythmic way I tend to favor playing a 4-string. About the only drawback is I can occasionally be guity of overplaying with a 5-string if I don't watch myself. Probably because I play a 5-string with something resembling a guitarist's finger-style as opposed to my other basses. That (I'm guessing) is because with the narrower string spacing on my particular fiver, it's harder to get in between and "dig in" like you can with the wider 4-string spacing. So that tends to keep my already fairly light touch more up on top of the strings, which makes it easier to fire off a lot of notes. I imagine if you're using one of those bass ramps the same thing could happen.
I never had to do anything to get myself "in the frame" for playing a 5-string per se. I approach every bass I play as being its own thing. So it was just natural for me to let the 5-string tell me what it wanted to do and then go along with it. It's hard to explain, but my brain just naturally seems to reprogram itself for whatever instrument I'm working with. I play a few other instruments and it happens with them as well. So it's not just with bass I do that.
Good muting technique is IMO even more important on a 5-string than it is on a 4-string.
The lower notes aren't really all that important to me except for having that convenient C and D below the low E because I play mostly rock and similar genres.
I don't consider a 5-string better or more advanced or versatile than a 4-string bass. I just see it as something different. Yet another bass range instrument that has its own advantages and disadvantages. It's good for some things, excels at others, and is about par with other choices - depending on the song or the genre it's being used for. Same goes for a 4-string. Or a 6-string for that matter. I like all types of basses and see no reason for not going back and forth as musical necessity or your whims dictate.
But I try not to overanalyze things like this these days. I prefer a more Zen-like approach and "just play" music. And as long as it sounds good and serves the song, I'm happy to let whatever I'm doing happen - and let it go at that.
That's my story. And I'm sticking to it. YMMV.
